18º 434 SBC Dyno Results

[Rick360]

Dynoed my newly built 434ci SBC and below are the results from the best avg pull. Tried 2 intakes, 2 cams, 2 carbs and 2 headers as well as tuning.

The build...with best performing parts (other parts tried described below)
4.155" bowtie block with 4.00" Ohio crank
Callies Ultra-XD 6" rods - 2.100" journal
Flat-top Diamond pistons for 14.5:1 compression
Dart 18º heads with 2.15" / 1.60" titanium valves
ported by me ...flow ... 370cfm intake and 280 ex
Edelbrock 18º 4150 intake (from the mid 1990's; also ported by me)
Spacer adapter to Dominator carb (1350 Ultra HP Holley)
COMP CAM 273/288 - 112LSA .800"/.688" with 1.7/1.6 Jesel rockers (std bearing diameter and base circle)
Morel .842" diam roller lifters
1-7/8" Dragster headers
Moroso vacuum pump
Hamburger box type oil pan with full kickout
Melling select internal oil pump
Sunoco Supreme 112 fuel

will be putting this in my dragster and making some runs soon as weather, work and wife permit.

RPM -- TQ - - HP
5300 - 657 - 663
5400 - 664 - 683
5500 - 667 - 699
5600 - 669 - 713
5700 - 674 - 731
5800 - 673 - 743
5900 - 682 - 766
6000 - 679 - 775
6100 - 680 - 790
6200 - 676 - 798
6300 - 673 - 808
6400 - 674 - 821
6500 - 667 - 825
6600 - 665 - 836
6700 - 657 - 838
6800 - 662 - 857
6900 - 656 - 862
7000 - 649 - 865
7100 - 637 - 861
7200 - 632 - 867
7300 - 622 - 865
7400 - 614 - 866
7500 - 606 - 866
7600 - 592 - 857
7700 - 593 - 869
7800 - 582 - 864

* The other cam tried was a Lunati 282/295 .800"/.740" on 114 and it was almost as good in the upper 500 rpm but was down on power at lower rpm.
* The other intake tried was Bowtie 18º ported by me but had smaller runners and less taper. It was down about 20hp
* The other carb was a stock Holley 1050 9375 carb. It was down on HP and TQ all the way thru compared to the 1350 Ultra HP
* The other headers tried were 2-1/8" to 2-1/4" step chassis headers and they were about the same above 7k rpm but down below 7k

Bigger is not always better ... but it seems to be when talking about a carb. The 1350 had a max of 0.7"Hg manifold vacuum and the 1050 was 1.1"Hg max. If the carb can still atomize and meter the fuel the bigger the better.

Comments / suggestions ...

Rick

[stokerboats]

Nice job!!!!!

[Warp Speed]

Why such a big split in lift from intake to exhaust?

[mag2555]

Why are the TQ numbers and hence the HP numbers bouncing all over the place?

[jmarkaudio]

I'd be curious about the bouncing numbers too. As far as the 1350 carb, did you run any O2 sensors? Any calibration changes? I have a 1475 Gen 3 I've not had the chance to mess with yet, can you map the calibration on that carb, I'd like to see how it compares to mine.

[steve316]

2 HP per cu in with 434 sb ; those tq numbers very 3# at most, is about 1/2 a percent . I would be worried about how to get it hooked-up.

[CGT]

FLOWZ!

[Rick360]

Why such a big split in lift from intake to exhaust?

.800" with 2.15" valve = .372 L/D ratio
.688" with 1.60" valve = .430" L/D ratio
How much lift does the ex need? Would more ex lift make more power? I would like more intake lift but don't feel good about it with stock cam journal.

Why are the TQ numbers and hence the HP numbers bouncing all over the place?

Look fairly normal to me. Dyno is a Stuska and some variation between rpm samples is always there thats why averaging rpm ranges to see gain/loss is always better than looking at any single number. Some dynos filter and average the numbers more than others to make it look smooth. Do you think it is a problem?

As far as the 1350 carb, did you run any O2 sensors? Any calibration changes? I have a 1475 Gen 3 I've not had the chance to mess with yet, can you map the calibration on that carb, I'd like to see how it compares to mine.

The 1350 is an out of box Ultra HP with only minor jet and hsab changes. It had really good response and idle. O2 readings were good and flat thru the rpm range. It had been run on another similar 800+ sbc recently and was tuned more with it and was just about right when we tested on my engine. It is back on the other engine so I don't have access to it to get any cal info. I may buy one after seeing how well it worked.

Rick

[Rick360]

FLOWZ!

Is that a question, comment or request for flow #'s?

Rick

[CGT]

It was a comment, a question, and a request for possibly some details of the VJ, seat angles, .........Valve backcut?

[wyrmrider]

I'd just as soon see the dyno numbers without the "smoothing"
not a problem
nice torque curve
might work just as good with less ex lift but why mess with success unless ex valve lift is more than intake and exhaust is heavier than intake and you want to set the ex down easier or...

[andyf]

Great power for a 18 degree SBC. The new Ultra Dominator carbs from Holley are super nice carbs. Time to sell the old stuff and upgrade!

Have you run that engine thru PipeMax? It would be interesting to see what PipeMax wants for headers. Some 2 inch headers might be just right at that power level, the 1 7/8 headers seem a little small but evidently the bigger pipes you tried were too big.

Schoenfeld has fairly inexpensive dyno headers for SBC motors. Their dyno headers are so cheap I can usually talk myself into buying a set to R&D a new combo.

[bigjoe1]

I run 150 more lift on the intake than the exhaust on serious race engines all the time. It works for me too


JOE SHERMAN RACING

[Ed Wright]

I run 150 more lift on the intake than the exhaust on serious race engines all the time. It works for me too


JOE SHERMAN RACING

I thought everybody did.

[lada ok]

That sunoco fuel ... is it alcohol based ?